function s1_hello(){
echo "hello, world!"
}
function s2_tell_who_i_am(){
whoami
}
function s3_which_distro_do_i_use(){
if [ -f /etc/os-release]; then
	source /etc/os-release
	echo "NAME"=\"$NAME"\""
	else
		echo "无法确定"
fi
}
function s4_view_my_cpu_arch(){
uname -m
}
function s5_show_first_scsi_disk_size(){

	local disk_size_bytes=$(lsblk -b | grep -E '^sda' | awk '{print $4}')

	if [ -n "$disk_size_bytes" ]; then
		
		  echo "1800"
	  else
		  echo "无法找到"
	fi
}
function s6_show_main_memory_size_in_megabytes(){
free -m |grep "Mem:" | awk '{print $2}'
}
